Non-fouling spark-plug



P. L DONAVAN.

NON-FOULING SPARK PLUG.

APPLICATION FILED ocT. II, 19m.

1,372,489. Patented Mar. 22, 1921.

S n we VL 01 Jflonaran.

PATENT OFFICE.

PAUL J. DONAVAN, 01 DENVER, COLORADO.

N ON FOULI1\T G SPARK-PLUG.

Specification of Letters Patent.

Patented Mar. 22, 1921.

Application filed October 11, 1919. Serial No. 330,067.

To all whom it may concern:

Be it known that I, PAUL J. DONAVAN, a citizen of the United States, residing at the city and county of Denver and State of Colorado, have invented certain new and use ful Improvements in Non-Fouling Sparkllugs; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to spark plugsof the class designed to prevent accumulatlon of oil on the electrodes.

The object of the invention is to provide an electrode so constructed that the oil will flow readily from the spark points. This object is accomplished by providing the spark terminals of the electrodes with sharp points which are opposed to each other, and the axes of which are in alinement. In the drawing forming a part of the specification:

Figure 1 is a vertical section through a spark plug to which my invention is applied.

Fig. 2 is a fragmentary elevation of a modification; and

Fig. 3 is an end view thereof.

In the form shown in Fi 1 the usual porcelain core 10 and metallic shell 12 are provided. The core 10 contains an axially disposed electrode 14, which is pointed at its spark terminal as shown. The shell 12 is provided with a curved electrode 16, the spark terminal of which is pointed and is arranged in alinement with the spark'terminal of the electrode 14. The curvature in the electrode 16 is in the form of a fairly long curved neck or loop 18. The pointed terminals of the electrodes offer no substantial surface for the adherence of oil, with the result that these points will always be clean. Any oil that will tend to accumulate will find its way to the bottom of the neck 18 from which it will drop when the accumulations become sufficient.

In the form of Figs. 2 and 3, the shell 20 is provided with electrodes 22, the spark terminals of which are bent inwardly at right angles. as shown. The center electrode 2-4; is provided with spark terminals 2-1- in a number equal to the electrodes 22. The terminals 24 are directed in alinement with the terminals of the electrodes 22, all of the terminals being pointed as in the other form. In this form the tendency of oil which may accumulate will be to run to the lower sides of the terminals and leave the spark points clean.

The constructions herein shown will never result in short-circuiting, as it is impossible for a drop of oil to be deposited and fill the gap between the terminals. Thus a spark will always be produced and Inisfire from dirty plugs will never result. These constructions may be used either on vertical motors or on those of the V-type. They may also be used on any other type of motor.

I claim:

1. A spark plug, comprising a shell member. an electrode thereon. a core member, an electrode on the core, the spark terminals of said electrodes being pointed and opposing each other, one of said electrodes depending from the member in which it is mounted, the other electrode depending from its member and being provided with a reverse curve forming a neck between its point and the connection thereof with the respective member.

2. A spark plug having two electrodes, the spark terminals of said electrodes being pointed and opposing each other, one of said electrodes depending from the member in which it is mounted and being provided with a relatively long depending I'eversely curved neck between its point and its connection with the respective member. whereby oil may flow away from said point to prevent building up of carbon at said point.

In testimony whereof I aflix my signature.

PAUL J. DoNAvAN. 

